Human Neutrophil Elastase Through Tumour Necrosis Factor-? Converting Enzyme-epidermal Growth Factor Receptor Signaling Pathway Induced CRS Hypersecretion

Objective:The study aimed to develop nasal hypersecretion establish model in C57BL/6 mice,using HN E stimulate the nasal mucosa epithelium.To provide evidence of HNE-induced MUC5AC mucin expression via TACE-EGFR in mice.Methods:1.6-week old female C57BL/6 mice were randomly divided into two groups: NS group and HNE group.On 7 consecutive days,saline or HNE was administered to C57BL/6 mice by inhalation,mice were sacrificed 24 h after the last intranasal administration.We used HE staining and PAS staining to observe the pathological changes of each group.2.After successful induction,we give tumor necrosis factor-converting enzyme inhibitor(TAPI-2)or epidermal growth factor receptor inhibitor(AG1478)as intervention factors,then used HE staining and PAS staining to observe the pathological changes.The TACE,EGFR and MUC5AC protein expression in the nasal mucosa were detected via the immunohistocchemistry.The fluorescence quantitative PCR method to detect the expression of TACE,EGFR and MUC5AC m RNA.Using Western Blot to detect the protein expression of p-EGFF,EGFR and TACE in each group.The MUC5AC protein levels were detected by ELISA method.Results: 1.Compared to the control group,the HN E group showed that the epithelium irregular arrangement,hyperplasia of goblet cell,inflammatory cell and submucosal gland;the nasal mucosa showed a strong positive staining of fuchsia granules in PAS staining.2.The TACE,EGFR and MUC5AC expression showed significantly higher expression in HNE group than control group(P<0.01).The HNE+TAPI-2 group and HNE+AG1478 group had significantly less goblet cell,inflammatory cell,submucosal gland and PAS staining than the HNE group.The immunohistochemistry demonstrated a significantly less expression of TACE,EGFR and MUC5AC in the HNE+TAPI-2 group than the HNE group(P<0.01);the HNE+AG1478 group also showed obciously decreased in the expression of EGFR and MUC5AC(P<0.01),while,there had no difference in TACE expression between HNE+AG1478 group and HN E group(P>0.05).Compared to mice treated with HNE only,the HNE+TAPI-2-treated mice demonstrated the TACE m RN A and protein,EGFR m RNA and protein,MUC5AC m RNA and protein,P-EGFR protein was significantly reduced(P < 0.01);the HNE+AG1478-treated mice showed a significantly lower degree of the EGFR m RNA and protein,MUC5AC m RNA and protein,P-EGFR protein expression(P < 0.01),but there had no significantly difference in the TACE m RNA and protein expression between HNE+AG1478 group and HNE group(P>0.05).Conclusion: 1.Successfully developed a stable experimental model of nasal hypersecretion in mouse.2.TAPI-2 or AG1478 inhibited HNE-induced MUC5AC production,suggesting that MUC5AC mucin expression via a cascade involving HNE-TACE-EGFR signal path in vivo.